What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The certified flight instructor had been at work approximately 4 hours starting at 7:00 am before the accident flight, performing preflight and ground instruction duties. The prospective student pilot had been at the 14 CFR part 61 flight school for approximately 2 hours. The weather observation from the nearest weather station (klns) at 10:53 am indicated clear skies, winds from 170 degrees at 8 knots with no gusts and 10 miles visibility. The temperature was 12 degrees celsius, dew point was -01 degrees celsius, and the altimeter setting was 30.24 in hg.
The helicopter was near the completion of a ?discovery flight? And was hovering approximately 2 feet or less over the sod north of the parallel taxiway to runway 10/28 heading approximately 180 degrees. The terrain at the accident site slopes down toward the taxiway approximately 2 to 3 degrees. The instructor was demonstrating how the flight controls work while hovering by allowing the prospective student to come on one flight control at a time. The prospective student had control of the cyclic ?t? Bar while the flight instructor was guarding the cyclic. The helicopter was drifting laterally to the right when the flight instructor allowed it to settle. The rear of the right skid tube contacted and dug into the sod creating a pivot point. The lateral drift was not recognized nor arrested by the flight instructor, and the helicopter experienced dynamic rollover. Both main rotor blades struck the ground, shearing both main rotor pitch change links from the blade grips and the drive link from the swashplate. Both main rotor blades sustained substantial damage consistent with ground contact while under power. The flight instructor and prospective student pilot were uninjured.
As the FAA filed it
THE CERTIFIED FLIGHT INSTRUCTOR HAD BEEN AT WORK APPROXIMATELY 4 HOURS STARTING AT 7:00 AM BEFORE THE ACCIDENT FLIGHT, PERFORMING PREFLIGHT AND GROUND INSTRUCTION DUTIES. THE PROSPECTIVE STUDENT PILOT HAD BEEN AT THE 14 CFR PART 61 FLIGHT SCHOOL FOR APPROXIMATELY 2 HOURS. THE WEATHER OBSERVATION FROM THE NEAREST WEATHER STATION (KLNS) AT 10:53 AM INDICATED CLEAR SKIES, WINDS FROM 170 DEGREES AT 8 KNOTS WITH NO GUSTS AND 10 MILES VISIBILITY. THE TEMPERATURE WAS 12 DEGREES CELSIUS, DEW POINT WAS -01 DEGREES CELSIUS, AND THE ALTIMETER SETTING WAS 30.24 IN HG.
THE HELICOPTER WAS NEAR THE COMPLETION OF A ?DISCOVERY FLIGHT? AND WAS HOVERING APPROXIMATELY 2 FEET OR LESS OVER THE SOD NORTH OF THE PARALLEL TAXIWAY TO RUNWAY 10/28 HEADING APPROXIMATELY 180 DEGREES. THE TERRAIN AT THE ACCIDENT SITE SLOPES DOWN TOWARD THE TAXIWAY APPROXIMATELY 2 TO 3 DEGREES. THE INSTRUCTOR WAS DEMONSTRATING HOW THE FLIGHT CONTROLS WORK WHILE HOVERING BY ALLOWING THE PROSPECTIVE STUDENT TO COME ON ONE FLIGHT CONTROL AT A TIME. THE PROSPECTIVE STUDENT HAD CONTROL OF THE CYCLIC ?T? BAR WHILE THE FLIGHT INSTRUCTOR WAS GUARDING THE CYCLIC. THE HELICOPTER WAS DRIFTING LATERALLY TO THE RIGHT WHEN THE FLIGHT INSTRUCTOR ALLOWED IT TO SETTLE. THE REAR OF THE RIGHT SKID TUBE CONTACTED AND DUG INTO THE SOD CREATING A PIVOT POINT. THE LATERAL DRIFT WAS NOT RECOGNIZED NOR ARRESTED BY THE FLIGHT INSTRUCTOR, AND THE HELICOPTER EXPERIENCED DYNAMIC ROLLOVER. BOTH MAIN ROTOR BLADES STRUCK THE GROUND, SHEARING BOTH MAIN ROTOR PITCH CHANGE LINKS FROM THE BLADE GRIPS AND THE DRIVE LINK FROM THE SWASHPLATE. BOTH MAIN ROTOR BLADES SUSTAINED SUBSTANTIAL DAMAGE CONSISTENT WITH GROUND CONTACT WHILE UNDER POWER. THE FLIGHT INSTRUCTOR AND PROSPECTIVE STUDENT PILOT WERE UNINJURED.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.